Meeting Abstract
Sensory experiments require anesthesia so the animal is immobilized. Traditional fish anesthetics (e.g. tricaine) depress the sensory system, although the degree to which results are affected is unclear. Newer anesthetics, such as propofol, may offer the same anesthetic relief, but the action of propofol differs from tricaine, so sensory responses may not be affected. Propofol has been used intravenously on small elasmobranchs but may provide prolonged effects if used as an immersion anesthetic. Due to its potential to maintain a surgical plane of anesthesia during sensory physiology experiments, investigation of propofol as an alternative anesthetic warrants investigation. The objectives of this study were 1. Determine the appropriate dose of anesthesia to minimize induction and recovery time for animals anesthetized at a surgical plane of anesthesia and 2. Measure physiological response of the pupil to light stimuli during anesthetic immersion. To address our objectives, we used the coral catshark Atelomycterus marmoratus. Respiration rate and response to mechanical stimuli were recorded to measure induction and recovery times in 8 tricaine and 7 propofol doses and generate dose response curves. Appropriate doses of anesthesia are approximately 175 mg L-1 tricaine and 1.25 mg L-1 propofol. After 1.5 hours of dark adaptation in an anesthetic bath (50, 100, or 150 mg L-1 tricaine or 0.5, 1, or 1.5 mg L-1 propofol) or no anesthesia (control), tricaine 100 mg L-1 trials show reduction in percent pupil constriction (p<0.5; ANOVA). While these results suggest propofol may be appropriate for use in sensory experiments, anesthetics are often species specific so the effect of propofol immersion in other elasmobranch species will be investigated.
